000
FXUS64 KLUB 061113
AFDLUB
Area Forecast Discussion
National Weather Service Lubbock TX
513 AM CST Tue Dec 6 2016
.AVIATION...
Breezy conditions are expected to continue before gradients relax
around mid-day with winds becoming southerly by sunset. Some risk
of MVFR clouds will exist at KCDS tonight along with a risk of fog
at KLBB/KPVW toward sunrise Wednesday morning.
&&
.PREV DISCUSSION... /issued 420 AM CST Tue Dec 6 2016/
SHORT TERM...
The first of two cold fronts has made it through the CWFA with
chilly and gusty winds in its wake. Zonal flow is present over West
Texas this morning and this is the predominant regime for the next
week. However, an impressive and quite wide trough is positioned to
our north with a parent low up near Lake Superior. Another burst of
energy will dive down the western side of the major trough with a
subtending feature that will bring the coldest air of the season
into Thursday. The upper level winds driving these features will be
racing out of the Pacific Northwest and approaching 140 kts. Thanks
to the increasing trough strength to our west in response to the
upper low, winds will turn around quite rapidly despite the strength
of the initial push. That is to say, by mid-afternoon, return flow
will already be established out west and some hints of cyclogenesis
in SERN NM are present in the data by sunrise Wednesday. More about
the second front in the extended below.
A batch of high clouds has arrived pretty much on cue along with
some limited low clouds in our northeastern zones. Indications are
that the low clouds will hang around, to some extent, in the
Rolling Plains during the day. Thence, into the overnight hours,
the return flow will help sustain and increase low cloudiness back
up in to the Texas Panhandle. At this point, a scattered to broken
layer looks most likely.
LONG TERM...
Wednesday will be a day of big change as the second of our two cold
fronts for the week rushes through the forecast area. Slight
compressional heating will occur ahead of the front and combined
with a brief clearing of skies, Wednesday highs should be able to
breach the 50s across all but the far northern portion of the
forecast area where the front will begin to impact temps by early
afternoon. Lows Thursday morning will be some of the coldest, if
not coldest, we have seen this season. Two things that may save us
from the bottom completely falling out (i.e. lows ranging from the
single digits to teens) are the winds look to stay up through most
of the night and clouds (low and high level) should be slow to
clear. Should these factors change, lows Thursday morning will
easily be several degrees colder, especially across the northwest.
Decided to pull highs down on the Caprock just slightly for
Thursday from the blend output. Temperatures in Montana and
southern Canada are currently running between one and three
degrees below current model runs. Even though there will be some
modification of the airmass as it travels southward, and yes,
skies will clear on Thursday afternoon...H850 temps between -5 and
-7, temperatures on the Caprock should stay in the lower 30s.
Past this, we return to rather flat zonal flow that brings calm and
warmer weather with it. A trough will pass to the north on Sunday
pushing a weak cold front through, though, highs on Monday will be
only a few degrees cooler. Otherwise, the 60s will be back by this
weekend, so this cold spell will be relatively short-lived.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
99/99/26